Hither-to, the RFID technology has been widely used for the purpose of product management. In a case where IC tags are attached to linen goods such as uniforms or bed sheets used in a hotel, the IC tags will be washed with the linen goods in the laundry. Therefore, the IC tags attached to such goods need to have strength against external forces and resistance against solutions used in the laundry process. A known IC tag to be attached to linen goods is provided with a covering made of a rubber material to cover the body of the IC tag.
However, in the dewatering step of the laundry process, strong bending and twisting forces and a pushing load act on the above-described IC tag, possibly causing breakage in the vicinity of the connection of an IC chip and an antenna part. Such a situation will be described with reference to FIG. 6. FIG. 6 is a plan view of an IC tag according to a prior art. In FIG. 6, the covering is not illustrated.
As shown in FIG. 6, the IC tag 200 includes a film member 210, an antenna part 220 provided in the film member 210, and an IC chip 230 mounted on the film member 210 and connected to the antenna part 220. While the thickness of the antenna part 220 is thin, the IC chip 230 has a large thickness. Specifically, while the antenna part 220 is made of a thin film such as a copper foil, which is very thin, the IC chip 230 has a thickness of approximately 0.5 millimeter. Therefore, when bending and/or twisting force acts on the IC tag 200, stress will concentrate at a portion in the vicinity of the connection of the antenna part 220 and the IC chip 230 (i.e. the region indicated by X in FIG. 6). Consequently, breakage can occur in the vicinity of the connection.
As countermeasures against breakage caused by concentration of stress, a technique of providing slits in the film member on both sides of the IC chip (Patent Document 1) and technique of reinforcing the connection of the IC chip and the antenna part using a reinforcing plate or the like to reduce the effect of bending stress (Patent Document 2) have been known. However, the former technique is unsatisfactory as means for protecting the portion near of the connection of the IC chip and the antenna part in cases where a pushing load acts, as is the case in the above-described dewatering process. On the other hand, the latter technique leads to the problem of complex structure. Therefore, there is yet room for improvement.